The math being used to solve the electricity grid’s most complex power flow equations today is, well, kind of fuzzy.
Gridquant, a startup created by Spanish software development firm Grupo AIA, says its new math for power flow modeling can make those grid calculations far more accurate. While the company was only recently incorporated in the United States, versions of its “Holomorphic Embedding Load-Flow Method” (HELM) modeling have been put into action at grid operations centers by Spanish utility Endesa and Mexico’s Comisión Federal de Electricidad since the 1990s, as well as since 2002 at California utility Pacific Gas & Electric (PDF).
Last month, Gridquant announced that research heavyweight Battelle has joined as a new partner to bring its HELM technology to a wider audience. Battelle invested an undisclosed amount in the Savannah, Ga.-based company, and will take its technology to market as exclusive provider of consulting services for utilities wanting to implement the technology via end-use licenses.
The idea is that Battelle, the Columbus, Ohio-based group that helps run $6.5 billion in annual research and development budgets for customers including Department of Energy laboratories, can help utilities wrap their heads around building an unfamiliar and extremely complex form of mathematics into their grid operations.
“This software is a game-changer,” is how Bob Stuart, the former PG&E operations engineering manager who led the deployment of the technology at the utility in 2002, put it. “It does something totally different from Newton-Raphson, which has been around for a long time, but does not solve the problems you need it to solve.”
Stuart, who now works for Gridquant, is referring to the Newton-Raphson method, named after mathematical genius Sir Isaac Newton and his less well-known contemporary Joseph Raphson. For the past 100 years or so, these mathematical techniques have been used by energy management systems (EMS) to calculate power flows in the world’s grid operations centers.
But Newton-Raphson does so using approximations, and can yield false conclusions, especially when the data coming into the system is rapidly changing, Stuart said in an interview last week. That’s a problem, because those moments of rapid change also happen to be the moments of highest grid stress and danger. That means, ironically, that the flaws of the Newton-Raphson method make it least useful when the need for it to be accurate is at its most critical, he said.
Gridquant’s math, developed by physicist and Grupo AIA co-founder Antoni Trias-Bonet, takes a completely different approach, one that Stuart described as “deterministic” in approach. Instead of approximations that get less reliable as complications increase, HELM yields a verifiable result based on incoming data that’s constantly being built into the model, he said.
As Ross Harding, Gridquant’s CEO, put it, “This software shows you exactly where you are, where you want to go, and how to get there.” The software can integrate with existing EMS systems, which means it can incorporate existing grid sensors, such as synchrophasors that take millisecond readings of transmission system power quality.
Sensors like these are seen as a critical first step toward giving grid operators the visibility to foresee the kind of unpredictable cascading fault effects that lead to system-wide outages like those that struck the U.S. Northeast and Canada in 2003, or blacked out San Diego’s grid last year, or cut power across two-thirds of India last week.
But as Jason Black, grid systems research leader at Battelle, noted, “One thing synchrophasors can’t do is tell you what will happen if a line goes down, or makes a change.” Gridquant’s system can build on the synchrophasor data to provide grid operators a list of actions they can take to help bring the synchrophasor-detected grid anomalies back into a safe range of operations, he said.
While today’s EMS systems also strive to deliver that kind of analysis and insight to grid operators, using Gridquant’s mathematical models “may find problems on the grid that may not be seen by existing EMS,” Black said. They’re even more useful in managing situations where the Newton-Raphson method yields even fuzzier and less reliable results, such as so-called “N-minus-1” contingency planning, or figuring out how a grid will operate as generation and transmission assets are added or dropped from the mix.
Stuart sees several roles for Gridquant to play in today’s power grids, based on how he saw the same math used at PG&E:
- First, it can be used to allow the grid to operate more reliably on the margins of safety, by more accurately modeling just how much power is actually flowing through transmission lines and substations.
- Second, it can be used for the daily 'what’s happening tomorrow' briefings in which grid engineers plan for a whole host of contingencies that may arise during the course of a day of operations, he said.
- Third, it can be used to restore the grid once it’s gone down, he said. So-called 'black-start' operations are complex, with grid operators trying to orchestrate the restarting of multiple generation plants and the reconnecting of loads in a balanced manner.
Beyond plugging into these existing grid operations needs, Stuart sees a growing need for technologies like Gridquant’s to solve the new problems emerging with the growth of intermittent wind andsolarpower on the grid, the spread of plug-in vehicles, and other grid-disrupting technologies.
“The grid today, with what’s going on with growth, with renewables, is being turned upside down,” he said. “I’ve been at control centers all over where the operators don’t have that comfort of knowing exactly where they’re at.”
Neither Gridquant nor Battelle would discuss details of the company’s funding or plans for future developments of the technology, though Harding said that the company was in the process of seeking additional funding.
The two companies will also have to overcome a certain uncertainty in the utility industry over such a novel approach to an age-old way of managing power calculations, Black said.
“There is absolutely an acceptance curve. The math is totally new,” he said. Still, Battelle did its due diligence on the existing deployments in Spain, Mexico and California, and found examples where the utilities involved described real-world benefits of using the new math to catch grid anomalies or inefficiencies that traditional EMS platforms didn’t, he said.
That’s important, because utilities will want to find a set of benefits to outweigh the costs of deploying Gridquant’s technology. Harding said that could range from $50,000 or so for a simple, off-line analysis tool that doesn’t actually link up to the grid, to several millions dollars for installation on a full operational basis.
Of course, the benefits of avoiding the massive blackouts could be included in that calculation. As Gridquant’s novel math is put into place at more utilities, it will have more chances to prove whether or not it can actually give operators the tools to prevent blackouts they otherwise wouldn’t have seen coming.